Asked what view he took of the risk of recurrence in 1999, Prof Meadow said it was "tiny, and for clinical purposes probably not meaningful".

He added that he had an interest in cases where there were a lot of deaths and knowledge of such details led him to take a particular interest in the recurrence rates of sudden infant death syndrome.

Sir Roy also gave evidence as an expert witness in the trials of two other women, Angela Cannings and Donna Anthony, who were both freed on appeal after being convicted of murdering their children.

He told the GMC he had concerns over the evidence he saw regarding both Harry and Christopher's deaths.

"I could not think of natural causes for the two deaths," he said.

'In contempt'

Sir Roy began his defence on the same day the Lancet published its commentary on the case.

Editor Dr Richard Horton said Sir Roy had been a "lightning rod of blame" for the wrongful conviction of Mrs Clark.

"This misconceived pursuit of one man is wrong and threatens the effective delivery of child protection services in Britain."

But, in a statement, Mrs Clark and her husband Steve said: "We are surprised that the editor of a respected professional journal felt it appropriate to publish such partisan comments like this at such a time," they said.

"If the editor of a national newspaper had done the same in the middle of a criminal trial, on the day when the defence was due to open its case, then he might well have found himself in court for contempt for attempting to prejudice the outcome of the proceedings."

The case was adjourned until Monday morning when Prof Meadow will continue to give evidence.